Missing The Common Sense Element: The Full Field CBCT Issue Revisited

by Janice Goodman, DDS

Janice Goodman is a fellow of the American Academy of Cranial Facial Pain and is presently pursuing her Masters of Oral Medicine and Orofacial Pain at USC, LA. She devotes a large portion of her dental practice to TMJ and sleep dental medicine in downtown Toronto, and is the general dentistry member of the Oral Health Editorial Board.Every once in a while, certain individuals or groups are able to make restrictions and protocols for the entire profession that are simply missing the element of common sense. Once the restrictions are in place, it takes a monumental effort to change them so that they are more practical and fair. Very often it involves politicians who request the help of “experts” in a field to help guide them to make the rules. Often the “experts” have their own agendas or are more academically oriented and neither the public nor the profession are well served by the legislation.

CBCT is now considered the number #1 diagnostic tool in the USA. We don’t necessarily treat to Xrays, but, we need the tool to diagnose and eliminate pathology. The new CBCT units allow for “quick scans” (iCAT), and the radiation involved in a full field quick scan is less than 12 microsieverts, which is lower than a typical panorex. These scans may have less detail than a medical CT scan, but they are excellent for craniofacial examination and looking at structures like TMJ and airways. A regular CBCT full field of view scan is about 20 microsieverts (Dr. Dale Miles), which is miniscule radiation compared to thousands of microsieverts of a medical CT. In addition, small FOV (field of view) CBCT with a high SP (spatial resolution) can have more radiation than a large FOV with lower SP (Dr. David McDonald). A 3D CBCT affords more and better information than a 2D panorex or cephs. Full or limited fields are not that much of a difference in radiation exposure, especially when you are stitching them to get a bigger picture. Dentists use ALARA principles (As Low As Reasonably Achievable), to determine which Xray to take. There is no longer an issue about protecting the population from radiation with the new machines and proper and responsible education of the dentist owner. The public has been put at risk by decreasing the standard of diagnostic care.

Ontario is an island unto itself when it comes to legislation to prevent dentists from using large FOV CBCT. Ontario radiologists have said that dentists should not look further than the dental alveolar structures – how backward to the way that dentistry has developed becoming more “holistic” and involving more than just the teeth. Our scope of practice surely involves at least the stomatognathic system. Other than radiation issues, it was argued that most general dentists were incapable of learning to read a full field CBCT and could be held liable should they miss pathology. This would include dentists who were specialized in orthodontics, oral medicine, craniofacial issues, anatomists, pathologists, oral surgery (without 50 cases with a radiologist mentor), etc. This is simply an insult to the profession. Radiologists are not prepared to read and report CBCT’s for the information that some of these fields require. I tried to order a CBCT for a patient recently and no radiologist was able to accommodate the patient who was only in Toronto for a limited time. It is not right that the patient went without because of a bad political ruling. There are only a handful of radiologists in all of Ontario.

I find it disturbing that the Ontario Dental Association was invited to the moratorium to approve CBCT in Ontario and declined participation at that time. Perhaps they were not aware of the gravity of the subject then, and maybe it’s time for them to revisit it now. The Royal College of Dentists was supportive to allow dentists to own and take full field CBCT, but, without the support of the ODA, their opinion carried little weight. The college has no choice but to uphold the Ministry of Health’s current rulings. It is going to take a monumental effort by the dentists of Ontario to bring back the standard of care that they were once admired for.

There are other examples of this phenomenon in the dental profession. Equating treating one’s spouse with possible sexual abuse for the entire dental profession was outlandish. After much cajoling, petitions and energy, it looks like the restriction will soon be lifted. Presently, something similar is happening with dental sleep medicine in Canada, with a small group attempting to make the sub-specialty an exclusive area to practice in.

The difference in confidence levels with 3D versus 2D radiographs is huge. We understand that children and adolescents are most sensitive to radiation effects and dentists have a responsibility to be especially conservative and gentle in radiation doses with the younger populations. We are willing to take courses and exams and get whatever accreditation that shows that we will do no harm. Dentists need the ability to become educated and take whatever Xray is necessary, that gives off the least radiation, to best serve each individual patient. Ontario’s CBCT legislation needs to be revisited and soon. OH


Janice Goodman is a fellow of the American Academy of Cranial Facial Pain and is presently pursuing her Masters of Oral Medicine and Orofacial Pain at USC, LA. She devotes a large portion of her dental practice to TMJ and sleep dental medicine in downtown Toronto, and is the general dentistry member of the Oral Health Editorial Board.

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